1. Technical Field
The present invention generally relates to a vehicle door system. More particularly, the present invention relates to a multi-functional vehicle door system having a common door lower.
2. Discussion
Doors for motor vehicles are often made as unitary structures for enclosing the entire door opening of a motor vehicle body. The lower housing portion of the door structure typically carries a window regulating mechanism which displaces a window panel between a raised position at which the window panel covers the upper portion of the door opening, and a retracted position in which the window panel is recessed within a cavity in the lower housing portion. The lower housing portion is generally formed from an outer panel and an inner panel which define the cavity therebetween adapted to receive the window panel. The lower housing structure also includes door closure actuating means such as a latch mechanism and means for hingedly securing the door within the door opening of the vehicle body.
It has also been known to construct a vehicle door from separate upper and lower portions. In particular, early car models often included a door panel hingedly secured to the vehicle body which covered only a lower portion of the side opening of a vehicle. The top of the side opening was then covered by a separate panel or other window housing separately secured to the vehicle body. In addition, it has been known to hingedly or slidably secure the upper panel or housing to the lower door structure, but such constructions have typically permitted only limited displacement of the upper panel. For example, some previously known upper panels merely overlap the lower door structure or an adjacent body panel of the vehicle, and can obstruct areas within the vehicle passenger compartment.
Commonly owned U.S. Pat. No. 4,716,682 to DeRees discloses a modular door having a lower door housing defining a cavity adapted to receive a glass panel, and an upper cassette including a housing carrying a track for displaceably mounting the glass panel with respect to the upper housing and a regulator for controlling displacement of the glass panel along the track. The cassette is removable attached as a unit to the lower door housing to selectively expose the passenger compartment through a large portion of the door opening in the vehicle body. The lower housing is hingedly secured to the vehicle body within the door opening and wholly supports the upper housing of the cassette. The door unit seals against a weather seal extending around the periphery of the door opening when the glass panel is displaced to its fully extended position. U.S. Pat. No. 4,716,682 is incorporated by reference as if fully set forth herein.
While known door systems, including but not limited to the type shown in U.S. Pat. No. 4,716,682 provide certain advantages, they are all subject to improvement.